What is CVE-2025-21994?

CVE-2025-21994 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 5.15 onward and patched in 5.15.180, 6.1.132, 6.6.85 and others. CVE-2025-21994 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-21994?

CVE-2025-21994 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2025-21994?

Yes, CVE-2025-21994 has been patched. Fixed versions include 5.15.180, 6.1.132, 6.6.85 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-21994 actively exploited?

CVE-2025-21994 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-21994

Medium

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix incorrect validation for num_aces field of smb_acl parse_dcal() validate num_aces to allocate posix_ace_state_array. if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) It is an incorrect validation that we can create an array of size ULONG_MAX. smb_acl has ->size field to calculate actual number of aces in request buffer size. Use this to check invalid num_aces.

Package Linux Kernel

Published 2025-04-02

Last modified 2025-11-03

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 5.15 and later are affected. Fixed in 5.15.180, 6.1.132, 6.6.85, 6.12.21, 6.13.9, 6.14 and their respective stable series.

Affected from

≥ 5.15

Fixed in

✓ 5.15.180 5.15.x ✓ 6.1.132 6.1.x ✓ 6.6.85 6.6.x ✓ 6.12.21 6.12.x ✓ 6.13.9 6.13.x ✓ 6.14

References

The following references provide additional information about CVE-2025-21994 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Debian Security
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
Kernel patch commit
https://git.kernel.org/stable/c/1b8b67f3c5e5169535e26efedd3e422172e2db64
Patch
Kernel patch commit
https://git.kernel.org/stable/c/9c4e202abff45f8eac17989e549fc7a75095f675
Patch
Kernel patch commit
https://git.kernel.org/stable/c/a4cb17797a5d241f1e509cb5b46ed95a80c2f5fd
Patch

6 patch commits total View all on NVD

Details

CVE ID CVE-2025-21994

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-04-02

Modified 2025-11-03

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-21994?

CVE-2025-21994 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.15 onward and has been patched in 5.15.180, 6.1.132, 6.6.85 and others. CVE-2025-21994 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-21994?

CVE-2025-21994 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2025-21994?

Yes — CVE-2025-21994 has been patched. Fixed versions include 5.15.180, 6.1.132, 6.6.85 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-21994 actively exploited?

No — CVE-2025-21994 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.